I keep losing on slots and I don't know what I'm doing wrong

I feel like I have no clue what I'm actually doing and I'm just picking random games. The other day I found a slot that said it had 96% RTP and I thought okay that sounds pretty good. I know that doesn't mean I am gonna always hit big but I wasted $40 and barely hit anything. Is 96% not actually that good or am I misunderstanding what RTP even means because it definitely did not feel like I was getting 96% of anything back.

Also what is the deal with volatility? Nobody really explains it in a way that makes sense but I keep seeing it everywhere! Some slots I play give me tiny wins constantly and others I get nothing, then randomly get a decent hit! Is that what volatility means or is there more to it than that? Bonus rounds confuse me too. Some games have a buy bonus option where you pay like 80x your bet to go straight into the feature. I tried it once on sweet bonanza and got back less than what I paid to trigger it so that kind of turned me off from it. Are these even worth it?

I just want to stop feeling completely clueless every time I open a slot game. Any tips for a beginner who's trying to actually learn would be awesome.